Brake mechanism.



W. P. GOLIINS.

BRAKE MEGHANISM.

APPLIGATIQN MLRD PEB. 24, 191s.

1 ,108,138. Patented Aug. 25, 1914 v V Y 7 @-23 .Wl Aglllllll @tn/6336. figg.' B. Tw/ventole UNITED STATES PATENT OFFICE.

WILLIAM P. COLLINS, OF BOSTON, MASSACHUSETTS, ASSIGNOR T0 AUTOMATIC AIR 'BRAKE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION 0F MASSA- CI-IUSETTS.

BRAKE MECHANISM.

Specification of Letters Patent.

Patented Aug. 25, 1914.

T0 all whom it may concern:

Be it known that I, WILLIAM I. COLLINS, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented new and useful Improvements in Brake Mechanisms, of which the following is a specification.

This invention relates to new and useful improvements in brake mechanisms, the object being to provide a simple, powerful and durable device adapted to control and to check the movements of a rotating member by fluid compression or by gradually retarding the discharge of fluid from the chamber within which one or more piston blades are adapted to be revolved.

The invention consists in the combination and arrangement of parts whereby the above object and certain other objects hereinafter appearing may be attained, as set forth in the following specification and particularly pointed out in the claims.

Referring to the drawings: Figure 1 is a transverse section, partly in elevation, of a device embodying my invention, parts of said device being broken away to save space in the drawings. Fig. 2 is a section, partly in elevation, taken on the line 2-2 of Fig. 1, parts of this figure also being broken away to save space in the drawings. Fig. 3 is a detail section taken on the line 3-3 of Fig. 1. Fig. 4 is a detail section of a modified formof piston.

Like numerals refer to like parts throughout the several views of the drawings.

In the drawings, 5 is a rotary member which is mounted upon a shaft 6 journaled to rotate in bearings 7, 7 in a casing 8, said casing comprising a chamber 9 within which said member 5 is arranged to rotate. A portion of the wall of the casing 8 is arranged concentric with the median axial line of the shaft 6, this portion extending from the point 10 in the direction of the arrow a to the point 11, Fig. 1. The remaining portion of said casing 8 is oiset. The inner wall 12 of said oiset portion is preferably eccentrically arranged relatively to said median axial line and forms a crescentshaped chamber 13 which extends from the point 1G to the point 11 between the wall 12 and the periphery 14 of said rotary inember 5.

The chamber 13 is provided with ports 15 and 16 arranged adjacent to the opposite ends thereof respectively. These ports extend outwardly from the wall of the casing 8 and through stems 17 which are provided with means adapted to open and close the same. The preferred means for opening and closing said ports consists in forming a series of sharp pitch screw-threads 18 about the outer faces of the stems 17. Caps 19 also having screw-threads adapted to engage the threads 18 upon said stems respectively are each provided with a lever 2O secured to said caps and by means of which a rotary movement may be imparted to said caps 19. These caps 19 are provided preferably at the outer end thereof with perforations 21 which, through the rocking or rotating of said caps 19, are adapted to be closed by the end 22 of their respective stems. The stems 17 are also provided with passages 23 which are slightly staggered about the peripheries of said stems and are' so arranged that during the rotation of Athe caps 19 they will be gradually closed thereby. The levers 20 are preferably connected at their outer free ends by a link 24 which causes said levers to be rocked in unison to simultaneously open and close the passages or ports 15 and 16, and to the link 24 motion may be imparted by any suitable operating device, such for instance, as the lever 25.

The rotary member 5 is preferably made hollow by the recesses 2G and 27 formed at opposite ends thereof. The rim 28 surrounding said recesses is provided with a series of radially disposed slots 29 which extend through said rim and terminate in the web 30. lVithin these slots 29 are slidably arranged piston blades 31 which are provided with grooves 32 at their outer ends containing bars33 extending longitudinally of the blades 31 and yieldingly retained in contact with the inner wall of the casing 8 by springs 33 arranged at intervals beneath said bars. As the member 5 is rotated within the casing 8, the bars 33 will naturally contact with the inner wall of the portion of said casing which is concentric with the medianpaxial line of the shaft 6. As said blades 31 approach the chamber 13 it will be obvious that unless said member 5 is rotating ata rate of speed rapid enough to force said blades outwardly by the centrifugal force thereof that the bars 33 will not Contact with the inner wall 12 of said chamber 13, therefore to insure a contact los between said bars 33 and said surface 12 drums 34 are provided within the recesses 26 and 27 and whose peripheries are substantially concentric with the inner wall 12, and as the member 5 is rotated in the direction of the arrow a the inner ends of the pistons 31 will contact with the outer pcripheries 35 of the drums 34 and Will be reciprocated within the slots 29 radially relatively to the shaft 6 to contact with said wall 12 from the point 11 to the point 10 substantially diametrically opposite said point 11.

To accommodate for wear between the ends of the blades 31, the drums 34 and the inner wall 12 of the chamber 13 each drum is preferably adapted to be expanded, the expansion of which is accomplished by forming said drum in two parts 36 and 37 which parts may be separated on the line 38 extending longitudinally thereof. The member 37 preferably telescopes the member 36 and is guided by pins 39 engaging lugs formed on said members 36 and 37 respectively, said members being normally held in their contracted relation one to the other by springs 40 upon the interior thereof. An adjusting screw 41 having screw-threaded engagement with the casing 8 extends inwardly from said casing and is provided with a tapered end 42, which is also screwthreaded and has screw-threaded engagement with the web 43 of the drums 34. Each of the drums 34 is provided with an independent adjusting screW Which is accessible from the exterior of the casing 8, said screws constituting supports for said drums. To prevent the drums from rotating Within their respective recesses the shaft 6 is adapted to pass through holes 44 formed in the webs 43 thereof.

It is sometimes desirable to positively lock the rotary member 5 to the casing 8, particularly when the device is used as a brake for motor vehicles, and when said rotary member is so locked movement of the vehicle will be absolutely prevented. To accomplish this result, the end of the rim 28 is provided with oneor more segmental slots 45, which are adapted to receive the end of a pin 46 having screw-threaded engagement with the casing 8 and Whose screw-threads are of exceptionally steep pitch thereby requiring but a slight rotary movement of said pin to cause the end thereof to move into one of said slots 45. A lever 47 is secured to the outer end of the pin 46 and this lever may be connected, as desired, to means adapted to conveniently operate said pin to lock said members rela-tively to each other.

In Fig. 4, I have illustrated a modified form of piston blade in which the blade 3l is provided with a roll 48 which is arranged at the inner end of said blade 31 and may engage the face 35 of the drum 34.

The operation of the device hereinbefore specifically described is as follows: The casing 8 is preferably stationary while the member 5, secured to the shaft 6, is rotated with the rotating parts of the machine or vehicle to which the device is attached and during the normal operation of the device the ports 15 and 16 will be opened, as illustrated in Fig. 3, consequently as said member 5 rotates the piston blades 31 in passing through the chamber 13 will draw the air into said chamber through the port 15, as the member 5 rotates in the direction of the arrow a, until the piston arrives at the point b as up to this point said chamber has been gradually increasing in cross sectional area from the point 11. After the piston has passed said point b however the chamber 13 begins to diminish in cross sectional area and consequently the air or liquid, or Whatever the substance contained within said chamber may be, will be gradually discharged through the port 16, this action being repeated by the various blades constituting said series. When it is desired to check the speed ofthe rotary member 5 relatively to the casing, the lever 20 is oscillated to move the cap 19 lengthwise of the stem 17 in the direction of the arrow c Fig. 3, gradually closing the passages 21 and 23 and as said passages are closed the air will be prevented from discharging through the port 16 and consequently the air will be more or less compressed in advance of the pistons 31 but forming a partial vacuum at the rear thereof. After the member 5 has been brought to a stop by the means above described, and it is desired to retain said 'member stationary the pin 46 -is rocked by the lever 47 to cause said pin to project into one ofthe segmental slots 45, thereby positively locking said rotatable member to the casing 8. When it is desired to merely check the speed of the moving parts of the device rather than stop the same the cap "19 may be"V moved to only partially close the perforations 21 and the passages 23, thus permitting a small amount of air or liquid to enter through the port- 15 and to be discharged through the port 16.

Having thus described my invention, what I claim and desire by Letters Patent to secure is:

1. A brake mechanism having, in combination, a rotary member, a casing Within which said member is arranged to rotate, a portion of the Wall of said casing being olfset to form a chamber adjacent to a portion of the periphery of said rotary member, said chamber having ports at opposite ends thereof, a blade carried by said rotary member adapted to engage the inner Wall of said casing during the rotation thereof,means adapted to open and close saidports, means to lock said rotary member to said casing including a recess in said rotary member, a pin having screw-threaded engagement with said casing, and means to rotate said pin to move the same into and out of engagement with said rotary member within said which said carrier is arranged, said casing having a chamber arranged outside of and adjacent a portion of the periphery of said carrier, means adapted to create a relative rotary movement between said carrier and said casing, an expansibledrum adapted to engage said piston blades and reciprocate the same on said carrier during the passage of said blades through said chamber, and means to expand said drum whereby the length of the reciprocations of said blades will be varied.

3. A brake mechanism having, in combination, a piston blade carrier, a series of piston blades mounted on said carrier adapted to be reciprocated radially relatively thereto, a casing for said carrier provided with a chamber arranged outside of and adjacent to a portion of the periphery of said carrier, a split drum adapted to engage the inner ends of said piston blades and project the saine beyond the periphery of said carrier into said chamber, and a screw mounted in said casing, said screw having a tapered end adapted to be moved into said drum to expand the same and increase the projection of said piston blades beyond the periphery of said carrier.

4. A brake mechanism having, in combination, a piston blade carrier, a series of piston blades mounted on said carrier and adapted to reciprocated radially relatively thereto, a casing for said carrier provided with a chamber arranged outside of and adjacent to a portion of the periphery of said carrier, a drum arranged within said carrier adapted to engage the inner ends of said piston blades and project the outer ends of said blades into said chamber, said drum being split longitudinally thereof, springs adapted to yieldingly retain the 'sections of said drum together, and a tapered screw adapted to be moved longitudinally of said drum to expand the saine whereby the projection of said blades into said chamber may be increased.

5. A brake mechanism having, in combination, a piston blade carrier, a series of piston blades mounted in said carrier adapted to be reciprocated radially relatively' thereto, a casing for said carrier provided with a chamber arranged outside of and adjacent to a portion of the periphery of said carrier, a pair oi drums arranged within and adjacent opposite ends of said piston carrier, said drums adapted to engage opposite inner ends of said piston blades and project the same into said chamber, said drums being split Vlonfritudinallv s rin arranged in said L5 v7 D drums adapted to yieldingly retain the sections thereof together, and tapered screws arranged in said casing adapted to' be moved' into said drums to separate said sections whereby the projection of said piston blades into said chamber may be increased.

In testimony Whereo'l I have hereunto set my hand in presence of two subscribing witnesses.

VILLIAM P. COLLINS.

Vitnesses:

CHARLES S. GooDING, SYDNEY E. TArT. 

